Process for hydrogen treatment and catalytic cracking of petroleum hydrocarbons



July 19, 1960 H. BEUTHER ET AL 2,945,803

l PROCESS FOR HYDROGEN TREATMENT AND cATALyTIc CRACKING OF' PETROLEUM HYDROCARBONS Filed April 14, 195e Lag/Gar BY WL United Sttes PatetittOli Thisinvention relates tothe preparation" of lower-""boil-if' 5 ing-:materials from a crude petroleum which containls'sul-jf u'r andmetallifeous impurities.

Crude -vpetr'oleum's containingv relativelylarge `amounts of?"vanadium` andy sulfur constitute a diiiicultproblem inj re'gardto'conversion of the higher boiling rfractions into20 loyfve'rE boiling materials by catalytic cracking. The sul#v fuiandfvanadim `ixrlpurities have ra harmfulfeectonfthev i crackingcatalyst. Alssuchcrudesfrequently yield r l sidlua" having fa high-carbon residue so ,that they: cannot 4 Y. beicatalytically cracked without: depositionof large- "2 amounts of coke on the cracking catalyst.` A method' lfrequentlyusedto process such crudes is to 4distill` oitheff` lower-boiling fractions including vgas oil and'then' subject` "l th'e'undistilled residue to a coking operation. This colo-"fV ing"'5op'e'r`ation isnot attractive since itproduces'largef'30 an'ounts "of lowA value coke". Y p A, y,

This invention has for its object to provideanirn`` v proved procedure for the'conversion of crude pertoleum which rcontains metal and sulfur compounds into lower boilinghydrocarbonssuch as gasoline by procedu'rwhich 35 includes catalytic cracking.- Another object istoi'pr'of videveconmical procedure `for'the conversion ofpetroleff umfwhich'contains vanadium compoundsandfsulfurinto't lowe'r boiling hydrocarbons of higher value without form" ingfflargec-amounts of by-products Y of lowvalue. Anf-40 other object is to' improve'the stateof the art.`v Other objects will appear hereinafter.

These' and other objects of our'invention are accomff plishedby subjcting'fa crudepetroleumfwhich contains# sulfurffandvandiumto distillation to distill oif\"lower""`45 boiling fractions ofthepetr'olcum and to leave a residue` havinga weight percent sulfur to weight percent vanadium which equals at least ZOO--the'sulfurand Vanadium being?? determined on `the basis lof the amount oftheseelements`v present and not `the amount'of compound's'of these ele#V 50 mentsl-A Y Thisundistill'ed residue is subjectedto-treatmentv with hydrogen in the presence of a slulgf-activ'e hydrogena-v tion catalyst at a pressure between about 1750 and 4500 p.s.i.g., at a temperature from about 750 to 815 F., with a liquid hourly space" velocity from about 0.25 to 55 10A thepr oduct frorngthe hydrogenation is subjected to dis 'lation to remove materials boiling below gas oil whichfae' formed duringthe hydrogen treatment. The residuefrom -the Asecond distillation -constitutingmtheegas oil and-heavier components is then subjected to catalytic 250 Crackiney Y We' haveffo'un'dA in accordance 'witlfourV invention that" j -ec'e'iimical lccir'iversion intoa catalytic-crackingstoclcan i beobtainedbysubjecting only"the"higher*boilingcompol Y ratio approaches-'the minimum value 4of "2001* We1 pre Patented July 19, ,1960

Z f nentfsofj these 'low gradecrudes to the hydrogenatio'n treatment. Howven we have also Vdiscovered that ifpthe irstmentioned distillation, to obtainthe reduced crude, is "carried too-'fanv the'rsulfur-vanadium ratio is made toof low'jand'the'hydrogenationitreatment will not eiectively`- reduce'thevanadium'impurities toan extent Vsuliicielitto i' theresidue" In'other'words the initial distillation should notbefcarred to anextent suflicient to result in an undijstilled residt'havinga sulfurto vanadium ratio below ab`outn Z00.l `Othrv'vise it will not vbe possible during the"j hydrbgenatidn treatment to Vreduce the vanadiumcontent tofa sufficiently lowvalle lthatit will notgharmfully af# feclt-ftlie'ffcrackiligcatalystf Thuslthe ,vanadium content of pro'duc't after hydrogenation should be about"`o n`ef*` partpermillin orlessif `subsequent deactivation of 'thekl cracking catalyst is Kto be avoided. 'I'his value cannot be* obtained funl's's thefirst :distillation Ais carried out` only to 1an-"extent sucintto give a Vreduced crude charge stocl having a sulfur-'vanadinif-ratio above about 200; Y i p u Infthe 'followigexamples and description we have sett forth vseveral 'ofi the'prefe'rred embodiments' of our 'inven tion;I butfitiis'to be understood that they are given' byfA way'of' illustration only and `not irl-limitationthereof.r`v

Vanadium is known to have a harmfulV effect on"cata* lytic 'cracking catalysts. In order to ,avoid this: action thech'arg'est'ock to theA catalytic cracking operation shouldcontainles's than about one 'part' per'millionyoffV1 vanadiumi' The procedure of our invention isapplicatalZ to any crude petroleum or residual fraction thereof which* contains vanadium `in"amounts lsucienrt 'to rapidlyiand': adversely `affectV the activity of Va cracking catalyst `sut'zli'f:`

per million.N The charge 'stock to our procedure must-` contain; sulfur impurities in amount-s: between about 0.201` "1 4and I10.0` percent t by 4weight.' Of` coursey the sul/fur to"l vanadium ratio in the charge to the initial -distillation'must be 'above-'200.` Crudes which contain vanadium"firnpuri ties inlarge-amounts also usually contain sulfurimp'ulfi tiesfinl'argefarnunts. The invention thereforeis appli cabletoany crude petroleum or residual fraction thereoffY such as 'reduced or topped crude which contains sulfur-` and?? vanadium in thev amounts mentioned.

Theinitial distillation' has as its p'rimaryobjective the removal of lower boiling components of the "crude-pe-tlk troleum" such= as gasoline; fuel oil, etc." Thesestraight'f: run` fractiorstof `lower boiling point usually containrel at'iVel-y small amounts of" impurities;"particularly metall liferousfimpuriti'es, andcan beutiliied most economi'cll without subjectingthem to the hydro genation tre'atm'en' Thel obectivein` vthe rst' distillationA also' 'toi'iobtain ai*4 bottomsj fraction of smaller` volume' which cany '.bez more '1 economically treated in the more expensive hydto'gena'," tion cgperatioru'v VWhile itis necessary yfrom an economic standpoint -to .gutilizefasmaller `bottoms fractionV 'in-,thef-v hydrogenation treatment, nevertheless it is essential'that the distillation should not be. carried to a point vsuch that-1y the vsulfur-to vanadium ratiois below about 200. Other-.-v wisreuthe hydrogenation treatmentA will noterfectively .-reduce lthe 4vanadium content;V During'thel distillation Athe*` sulfur impurities'distill at a higher? ratethan 4the Vanadium and it Eis a Isimple matter tojfanalfyzellthpuis Vtillefd*'residue to determine when the i'sulfurto'vanaj fer to distill until a sulfur to vanadium ratio of between about 270 and 420 is obtained. The degree of distillation in the first distillation must be a balancing of two factors. On the one hand the low boiling fractions should be removed so that they can be utilized as such or processed by less expensive procedures than hydrogenation (i.e. direct scale or catalytic cracking of light oil and reforming of the gasoline). Gn the other hand the distillation should not be extensive enough to lower the sulfur-metal ratio below about 200. It Iwould of course be advantageous, if removal of vanadium was the only matter to be considered, to utilize yas high a sulfur. to vanadium ratio as possible. However, as pointed out above, this would means that the wholecrude would be subjected to the hydrogenation treatment, and this is. not ordinarily economically feasible. The amount of lower boiling matereials removed from the initial charge stock by the first distillation will depend upon the nature of the particular crude, such as the sulfur and vanadium impurity content and the amount of lower boiling components present. Therefore it is not possible to specify any degree of distillation in order to obtain the desired reduction in volume and minimum sulfur to metal ratio. However, as pointed out above, the degree of distillation required can be readily determined by analysis of the undistilled residue `during the distillation or by a small scale analytical distillation to determine the amount of distillation required. p

The undistilled residue from the first distillation is then subjected to the hydrogenation treatment. This hydrogen treatment is carried out by contacting the residue from the distillation with hydrogen under the conditions specified above while in the presence of a catalyst which retains its activity in the presence of sulfur compounds, i.e. a sulf-active catalyst. Examples of suitable catalysts are the oxides and suldes of group VI metals such as molybdenum, tungsten, vanadium, etc. used alone or in combination with oxides or suldes of iron group metals such as nickel, cobalt or iron. The catalysts may be uidized, i.e. suspended in the hydrocarbon vapors and hydrogen or may be in the form of a fixed bed. The catalysts may be composited with =a carrier such as activated alumina, Valumina-silica, AlfraX, kieselguhr, etc. T-he reaction conditions are preferably 2000 to 3200 p.s.i.g., 775 to 800 F. and a liquid hourly space velocity of 0.5 to 2. Hydrogen -is recycled at a rate of between about 1000 and 20,000 and preferably between about 2000 and 12,000 s.c.f./bbl. By utilizing these reaction conditions, the sulfur and vanadium are efficiently removed from the residual hydrocarbon charge stock with minimum concomitant conversion of the hydrocarbon into lower boiling materials and coke. Therefore by operating at these conditions, the heavy residual charge stock undergoes purification to a high quality catalytic cracking charge stock with relatively little conversion into lower boiling materials or formation of coke. Since there is little coke formed, the on-stream period for the hydrogenation is unusually long, i.e. about 150 to 4000 hours. Therefore relatively infrequent regeneration of the hydrogenation catalyst is required. After the catalyst has lost activity due to coke deposition, it can be regenerated in known manner by combustion with air or other oxygen-containing gas at a temperature between about 800 and 1400 F.

After the above described hydrogenation operation, the product from the -hydrogenation is subjected to a second distillation to remove the relatively small amount of lower boiling materials formed during the hydrogenation treatment. It is desirable to remove all of the material boiling below gas oil in this distillation. Thus gasoline and lower boiling fuel oils are preferably removed in this second distillation. The undistilled residue from this second Idistillation is then subjected to catalytic cracking. The invention has the unusual advantage that the initial procedures described above result in such an eth- 4 tion is carried out as described above, i. e. by observing the required sulfur-vanadium ratio, the nickel will be reduced to a low and harmless value along with the vanadium. In other words the hydrogenation treatment will reduce the vanadium content to below about one part per million with analogous reductions in nickel content and these amounts of metal impurities are not harmful to a catalytic cracking catalyst. Also the carbon residue is markedly reduced so that less coke is deposited on the cracking catalyst. The cracking catalyst may be any conventional or known cracking catalyst such as natural or synthetic silica-alumina cracking catalysts, cracking catalysts of high alumina-low silica content, silica-magnesia cracking catalysts, etc. The catalytic cracking operation may utilize either a xed bed or a fluidized bed, and the catalytic cracking conditions may be any conditions which are conventionally used.

In the accompanying drawing numeral 2 designates a fractionating column into which the charge stock which contains sulfur and metalliferous impurity is introduced via conduit 4. The charge stock is fractionated in column 2 and a light fraction is removed Via conduit 6. The undistilled residue having a sulfur -to vanadium ratio above about 200 is removed through conduit 8 and is mixed with hydrogen introduced through conduit 10. The mixture of these two components flows through conduit 12 into hydrogen treating zone 14 where the above described action resulting in lowering of the sulfur and metal content takes place. The product from the hydrogen treating zone flows through conduit 16 into still 18 where lighter portions formed during the hydrogen treatment are distilled olf through conduit 20. The bottoms fraction from still 18 flows through conduit 22 and is subjected to catalytic cracking in catalytic cracking zone 24. The products of catalytic cracking are then removed through conduit 26.

EXAMPLE A Middle Eastern, a Mid-Continent and a Venezuelan crude having the inspections shown in Table I were subjeoted to distillation to obtain reduced crudes. The Middie Eastern and Mid-Continent crudes were subjected to vacuum tower distillation and atmospheric distillation to obtain the reduced crudes and a vacuum reduced crude was prepared from the Venezuelan crude.

The atmospheric and vacuum tower bottoms from these crudes were then treated with hydrogen in the presence of the hydrogenation catalysts listed in Table II composited with an alumina carrier. The hydrogen treatment lwas carried out under the temperature, pressure, space velocity and hydrogen recycle conditions set forth in Table II. The atmospheric and Vacuum tower bottoms fractions treated had the sulfur-vanadium ratios set forth in Table II. The results of the hydrogen treatment on the sulfur, vanadium and nickel contents of the products are shown in Table II.

l*MEVTB:Middle Eastern vacuum tower bottoms. MEATB=-Middle .Easternatmospheric tower Mid-Continent vacuum tower bottoms.

crude.

4.From .the datapresented Table il, it lwill be .evident `that the utilization of a rsulfur to vanadium ratio above `about S200 resulted-in effective removal .of both sul-fur and vanadium., and specilically yielded products .having -thefdesired Z1 vpant per million or ,less of vanadiumwhich -is necessary jforcatalytic crackin-g charges.

Theffurnaceoil freeresidue -rom the .product obtained tnRun #6 of Table II wassubjected to catalytic .cracking. For comparison 1a Kuwait .gas 4oil was also matalytically Cracked under the same conditions (space velocitywt/hiz/wt. .of 1.5;temperature `of `930" and ".SlRfJFiltrol catalyst). Ithe inspections on the charge .stocks :to the catalytic cracking. are gi-ven in Table `IIII the inspect-ions on the products from catalytic crackdug are ,given in TableIV,

vTable III MCATB=MidContinent atmospheric tower bottoms. RVC=Reduced Venezuelan run fractions, said distillation being terminated .before a sulfur to vanadium ratio ybelow about 200 isi-cached, subjecting the `undistilledresidue from the first; distillation to .Contact with hydrogen `at a pressure between about 20001and 3,200 p.s.i.g., at a'temperature of between about 775 `and `800 F., at a liquid hourly space velocity be- ,tween about 0.5 -and "2 kat a hydrogen recycle rateof Fggnjgfclt gilwjf .3.5 betweenabout 2000'and 12,000.s.c.f./ bbl. in thepresence 1 From Rurl of` a stili-active hydrogenation catalyst, .subjecting the Y product from rthe hydrogenationtreatment to a 'second Inspoetgls f 670 Fi Producir 22 ,3 21 4 A,distillation gto remove materials boiling below about gas Percerf'slififj 21:1 (in 320.5 Oil :and ytoobtairr an undistilled residue constituting ,gas enseignantes; .te .te e@ @t1-educa 'boiling porties as sureste .the .uevanadium, Mlm -0 1 0, 7 distllled residuefrom the ,second -d1st1l1at1on without el1m 1 nat-ion lo f any of :the `,components thereof to .catalytic Table 1V cracking to convert the, ,undistilledresidue intoflower boill .ing hydrocarbons.

Fumane 0i, .Kwaimf 45 l13.7?1511@nuecess whichccmpris :in .Combinatonsub- FreejProduct ginGas- Oil .jectingja crude petroleum .which contains Narldium in FromfRun l amounts ,above 2 and below 1500 parts Vper millionztlllt y i b V l.. '71 4 6"0 0 slllfur infamounts between vabout 0.20 and110.0 .per,centby G Oil Con rs'on: percent y o ume- Cbompergeentlby Weight ,0 5 6.3 weight and whtch has a sulfur to vanadium'ratio above Deproparnzed Gasoline: Percent by V01- 61 3 53 5 50 200 to a iirst d1st1llat1on to remove lower boilmg straight me --r run lfractions said distillation being terminated before a Li ht Catal Gas O11: Percent by Voltime 15.2 20.0 sulfur to vanadium ratio below -about 200 1s reached, Rlelgegihibaciltgl 93,9 92.2 subjecting the undistilled residue from the first distilla- Research 3 ce. TEL 98. 7 96.1 t1on to contact with hydrogen at a pressure between about 2000 and 3200 p.s.i.g., at a temperature of between about reached, subjecting the undistilled residue from the irst distillation to contact with hydrogen at a pressure between about 1750 and 4500 p..s.i.g., at a temperature of between about 750 and 815 F., at a liquid hourly space velocity between about 0.25 and 10 at a hydrogen recycle rate of between about 1000 and 20,000 s.c.f./bbl. in the presence of a sulf-active hydrogenation catalyst, subjecting the product from tt@ hydrogenation treatment to a second distillation to remove materials boiling below abo'fzgas oil and to obtain an undistilled residue con- 775 and 800 F., at a liquid hourly space velocity between about 0.5 and 2, at a hydrogen recycle rate of between about 2000 and 12,000 s.c.f./bbl. in the presence of a catalyst selected from the groupy consisting of oxides and suldes of metals of group VI of the periodic system and oxides and suldes of group VI of the periodic system mixed with a member of the group consisting of oxides and sultldes of metals of the iron group, subjecting the .product from the hydrogenation treatment to a second distillation to remove materials boiling below about gas oil and `to obtain an undistilled residue constituting gas oil and higher boiling portions, and subjecting the undistilled residue from the second distillation without elimination of any of the components thereof to catalytic cracking to convert the undistilled residue into lower boiling hydrocarbons.

4. The process which comprises in combination subjectingka crude petroleum which contains vanadium in amounts above 2 and below 1500 parts per million and sulfur in amounts between about 0.20 and 10.0 percent by weight and which has a sulfur-to-vanadium ratio above 200 to a first distillation to remove lower boiling straight run fractions, said distillation being terminated before a sulfur to vanadium ratio below about 200 is reached, subjecting the undistilled residue from the first distillation to contact with hydrogen at a pressure -between about 2000 and 3200 p.s.i.g., at a temperature of between about 775 and 800 F., at a liquid hourly space velocity between about 0.5 and 2, at a hydrogen recycle ra'te of between about 2000 and 12,000 s.c.f./bbl. in the presence of a catalyst selected from the group consisting of oxides and sulides of metals of group VI of the periodic system and oxides and suldes of group VI of the periodic system mixed with a member of the group consisting of oxides and suldes of metals of the iron group, subjecting the product from the hydrogenation treatment to distillation to remove materials boiling below about gas oil and to obtain an undistilled residue constituting gas oil and higher lboiling portions, subjecting the undistilled residue from the second distillation without elimination of any of the components thereof to catalytic cracking to convert the undistilled residue into lower boiling hydrocarbons and continuing the above process for a period of time between about 150 and 4000 hours and until sufficient coke has accumulated on the catalyst to require regeneration, regenerating the catalyst by combustion and reusing the regenerated catalyst in the above process.

5. The process which comprises in combination subjecting a crude petroleum which contains vanadium in amounts above 2 and below 1500 parts per million and sulfur in amounts between about 0.20 and 10.0 percent by weight and which has a sulfur-to-vanadium ratio above 200 to a iirst distillation to remove lower boiling straight run fractions, said distillation being terminated when a sulfur to vanadium impurity ratio of about 270 to 420 is reached, subjecting the undistilled residue from the rst distillation to contact with hydrogen at a pressure between about 1750 and 4500 p.s.i.g., at a temperature of between about 750 and 815 F., at a liquid hourly space velocity between about 0.25 and 10, at a hydrogen recycle rate of between about 1000 and 20,000 s.c.f./ bbl. in the presence of a cobalt molybdate catalyst, subjecting the product from the hydrogenation treatment to a second distillation to remove materials boiling below about gas oil and to obtain an undistilled residue constituting gas oil and higher boiling portions and subjecting the undistilled residue from the second distillation without elimiv nation of any of the components Vthereof to catalytic crackn cs ing to convert the undistilled residue into lower boiling hydrocarbons.

6. The process which comprises in combination subjecting a crude petroleum to a rst distillation at atmospheric pressure to remove lower boiling straight run fractions vaporizable at atmospheric pressure, subjecting the undistilled residue from the first distillation to contact with hydrogen ata pressure between about 2,000 and 3,200 p.s.i.g., at a temperature of between about 775 and 800 F., at a liquid hourly space velocity between about 0.5 and 2 at a hydrogen recycle rate of between about 2,000 and 12,000 s.c.f./bbl. `in the presence of a catalyst comprising essentially cobalt molybdate, subjecting the product from the hydrogenation treatment to a second distillation to remove materials boiling below about gas oil and to obtain an undistilled residue constituting gas oil and higher boiling portions and subjecting the entire undistilled residue from the second distillation to catalytic cracking to convert the undistilled residue into lower boiling hydrocarbons.

7. The process which comprises in combination subjecting a crude petroleum to a first distillation at atmospheric pressure to remove lower boiling straight run fractions vaporizable at atmospheric pressure, subjecting the undistilled residue from the rst distillation to contact with hydrogen at a pressure between about 2,000 and 3,200 p.s.i.g., at a temperature of between about 775 and 800 F., at a liquid hourly space velocity between about 0.5 and 2 at a hydrogen recycle rate of between about 2,000 and 12,000 s.c.f./bbl. in the presence of a catalyst comprising essentially nickel tungstate, subjecting the product from the hydrogenation treatment to a second distillation to remove materials boiling below about gas oil and to obtain an undistilled residue constituting gas oil and higher lboiling portions and subjecting the entire undistilled residue from the second distillation to catalytic cracking to convert the undistilled residue into lower boiling hydrocarbons.

References Cited in the file of this patent UNITED STATES PATENTS 2,282,451 Brooks May 12, 1942 2,703,308 Oblad et al. Mar. 1, 1955 2,766,183 Porter et al. Oct. 9, 1956 2,775,544 Corneil et al. Dec. 25, 1956 2,801,208 Horne et al. July 30, 1957 2,902,429 Scott Sept. 1, 1959 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,945803 July 19., 1960 Harold Beuther et al.

' ror appears in the-printed specification of the above numbered patent requir ing correction and that the said Letters Patent should read as corrected below.

same line line lll,2 for Signed amd sealed this 4th day of April 1961c tm ERNEST W. SWIDER Acting Commissioner of Patents 

1. THE PROCESS WHICH COMPRISES IN COMBINATION SUBJECTING A MEMBER OF THE GROUP CONSISTING OF CRUDE PETROLEUM AND RESIDUAL FRACTIONS THEREOF WHICH CONTAIN VANADIUM IN AMOUNTS ABOVE 2 AND BELOW 1500 PARTS PER MILLION AND SULFUR IN AMOUNTS BETWEEN ABOUT 0.20 AND 10.0 PERCENT BY WEIGHT AND WHICH HAS A SULFUR-TO-VANADIUM RATIO ABOVE 200 TO A FIRST DISTILLATION TO REMOVE LOWER BOILING STRAIGHT RUN FRACTIONS, SAID DISTILLATION BEING TERMINATED BEFORE A SULFUR TO VANADIUM RATIO BELOW ABOUT 200 IS REACHED, SUBJECTING THE UNDISTILLED RESIDUE FROM THE FIRST DISTILLATION TO CONTACT WITH HYDROGEN AT A PRESSURE BETWEEN ABOUT 1750 AND 4500 P.S.I.G., AT A TEMPERATURE OF BETWEEN ABOUT 750* AND 815*F., AT A LIQUID HOURLY SPACE VELOCITY BETWEEN ABOUT 0.25 AND 10 AT A HYDROGEN RECYCLE RATE OF BETWEEN ABOUT 1000 AND 20,000 S.C.F./BBL. IN THE PRESENCE OF A SULF-ACTIVE HYDROGENATION CATALYST, SUBJECTING THE PRODUCT FROM THE HYDROGENATION TREATMENT TO A SECOND DISTILLATION TO REMOVE MATERIALS BOILING BELOW ABOUT GAS OIL AND TO OBTAIN AN UNDISTILLED RESIDUE CONSTITUTING GAS OIL AND HIGHER BOILING PORTIONS AND SUBJECTING THE UNDISTILLED RESIDUE FROM THE SECOND DISTILLATION WITHOUT ELIMINATION OF ANY OF THE COMPONENTS THEREOF TO CATALYTIC CRACKING TO CONVERT THE UNDISTILLED RESIDUE INTO LOWER BOILING HYDROCARBONS. 